1998 7.4 vortec in a 1961 Ford Body With a chevy blazer Frame.

[618 Syndicate]

It's the vats. You need to have it tuned out in the PCM. In your thread title you say 98 (which 100% had vats) but some (late) 97's did too.

 

[Badfish510]

How do I go about getting it tuned out and I don't have a place to check the codes I wish I did lol

 

[454cid]

The pcm might not like the transmission missing either, unless maybe it came from a manual truck.

 

[618 Syndicate]

How do I go about getting it tuned out and I don't have a place to check the codes I wish I did lol

Do you still have the obd port? If not you'll have to send the PCM off to get it tuned.
@Dropped88 may have ideas.

 

[Dropped88]

Sounds like vats does that pcm have 5 plugs or just 4

 

[someotherguy]

How do I go about getting it tuned out and I don't have a place to check the codes I wish I did lol

You'll want to have the ODB2 port in place and functional for other diagnostic purposes in the future. I always have to wonder about the thought process behind putting an EFI engine swap into an older vehicle but omitting the diag port. I've seen several examples of this. You're gonna need it every now and then to keep the vehicle running correctly.

As far as tuning it out you'll need an aftermarket tuning service to remove Passlock antitheft from the PCM. Not a whole lot of tuners work with the old "black box" PCM's like your 1998 donor truck had, so you'll need to shop around. I think Blackbear still does them.

Richard

 

[Badfish510]

Sounds like vats does that pcm have 5 plugs or just 4

4 plugs

 

[Badfish510]

4 plugs

There is a relay 4 or 5" from the pcm. What does that go to?

 

[someotherguy]

There is a relay 4 or 5" from the pcm. What does that go to?

No telling. Did you do this swap or did you buy the truck this way? Who deleted the OBD2 connector? I would strongly recommend looking up the 1998 factory service manual (there's links here on the site) and you should be able to determine from the wiring diagrams where the OBD2 connector used to be and how to wire one in so you can determine what's going on.

Richard

 

[Badfish510]

No telling. Did you do this swap or did you buy the truck this way? Who deleted the OBD2 connector? I would strongly recommend looking up the 1998 factory service manual (there's links here on the site) and you should be able to determine from the wiring diagrams where the OBD2 connector used to be and how to wire one in so you can determine what's going on.

Richard

I don't have any of the interior wiring just the firewall bulk head that plugs into the firewall connector